When the fourth season of the award-winning British family saga opened on PBS in January, 10.2 million of us turned on our tellys.

Fans relish the opulence and complications of life at the Crawley family's country estate.

Two of Maggie Smith's costumes are included in the exhibition.Nick Briggs, Carnival Film & TV, Ltd. 2011

We wait for Maggie Smith's Dowager Countess to deliver her imperiously wicked quips. We ache for Anna and hand it to Edith. We know that, deep down, gruff Carson cares and that the scheming under-butler, Thomas Barrow, is up to no good.

And we're keen on the clothes.

Delaware's acclaimed Winterthur Museum is banking on the drama's appeal as it prepares to open a major exhibition of 40 "Costumes of Downton Abbey" on March 1. It will run through January 4, 2015.

In addition to displaying costumes, the exhibition will compare life at Downton Abbey with the way of life at Winterthur, the childhood home and estate of collector and horticulturalist Henry Francis du Pont.

A day at Downton

The exhibition is organized by time of day, from morning to night, said Maggie Lidz, Winterthur's historian and one of three curators of the exhibition.

Anna's garden party costume is included in the exhibition. Nick Briggs, Carnival Film & TV, Ltd. 2012

A garden party, a wedding, a christening, summer whites, cold weather tweeds, valets and ladies maids, and evening entertainment are all featured.

"We made no attempt to reproduce the sets used for the television show," Lidz said. "Instead, we use color and dramatic lighting to highlight different settings throughout the day."

They also use photographs and videos that show actors wearing the costumes on display. All of the costumes in this exhibition are authentic. Actors wore them during the filming of the show's first three seasons.

"We wanted to have Carson's costume as part of the exhibition," said Kathleen Kiefer, a textile conservator.

"But he only wears one thing, so he uses his costume season after season. They decided to make him another so his costume could travel here."

Body-building

Kiefer is the exhibition's body-builder. She makes the headless mannequins on which the costumes are displayed.

"I look at the images of the actor on the show and try to convey their character. I do it with pieces of foam...and it works," Kiefer said.

I didn't appreciate how important that was until I saw Carson's unclothed torso...and recognized him!

Starting with a huge sheet of four-inch ethafoam (the kind used for packing) she starts carving a torso. But only after she's taken 10 or 12 measurements inside a costume to get the exact shape of the person we've grown to know.

"People have different silhouettes in different time periods," she explained, often because of their underwear. "If you wear a corset - like Mrs. Hughes might and Mrs. Patmore does - you can tell."

As the 1920s progressed, dresses became more natural.

The magic of Cosprop

View full sizeCostumes from the first three seasons of Downton Abbey awaiting placement in Winterthur's exhibition gallery. Ann Witmer

Most of the costumes come from a British company called Cosprop, one of the world's leading suppliers of authentic period costumes for film, television and theater.

"Its
talented costume designers almost always start with a 'piece of inspiration'
like a piece of vintage fabric," Lidz said. "They build a costume around it."

Like the wedding dress Edith wore when she was abandoned at the altar by old Sir Anthony in season three. The train of the dress is a lovely vintage piece of delicately embroidered, beaded fabric.

"They
built the gown around that small piece," said Joy Gardiner, Winterthur's senior
textile conservator. "The new gown doesn't duplicate the old piece, but it
matches."

Because of Downton Abbey, it's easy to assume that country squires everywhere lived like the Crawleys. But there were sharp contrasts between life on a British country estate and American country estates like Winterthur.

"In Britain, estates were kept within the family," said Lidz, whose book on American country estates, written with co-curator Jeff Groff, is scheduled for publication next year. "That wasn't so here. American country estates are about one person and their accomplishments, not family lineage."

In fact, she said, Americans turned their estates into public places that everyone can enjoy, like Winterthur and Longwood Gardens.

Another difference has to do with technology.

"Wealthy Americans have always filled their homes with the latest in technology that have made their lives more comfortable," Lidz said.

Not so in Britain. Remember Mrs. Patmore's horror when told that a refrigerator was about to be delivered to her kitchen? Or Cora's (Countess of Grantham) memorable quote? "I'm an American. I don't share your English hatred of comfort."

Language, too

"Americans didn't call hired help servants. They called them staff or employees. That emphasized equality and pay for labor. The British use of 'servants' indicated more of a class difference," Lidz said.

Formalities broke down more quickly in America although a footman did serve dinner at Winterthur up to the 1960s...and guests dressed formally for dinner.

Henry Francis du Pont realized his dream of turning his 175-room Winterthur mansion into a museum in 1951. He and his family moved into The Cottage, now the museum store.

A year of activities

The costume exhibition was the brainchild of Winterthur's director, David Roselle, a Downton Abbey fan.

Prior to this, Winterthur's most popular exhibition, Fashion in Film in 2006-7, featured Cosprop's period costumes from the screen.

The "Costumes of Downton Abbey" exhibition is included in the general admission price, but timed tickets (good for two hours) are required. To reserve, visit www.winterthur.org/admission and select general admission tickets. Or call 302-888-4600 or 800-448-3883.

Admission: Adults $20, children 2-11 $5, children under 2 free. Includes access to the "Costumes of Downton Abbey" exhibition, galleries, garden, garden tram tour, and an introductory house tour.